An Indian diplomat whose arrest in the US sparked protests from India has been formally indicted by a US grand jury.

However, prosecutors said that Devyani Khobragade, 39, had also been granted immunity and that officials had asked her to leave the US.

The Indian foreign ministry later said that she was on a flight back to India.

Ms Khobragade was detained on charges of visa fraud and of underpaying her housekeeper in New York last month.

India had demanded a US apology for her "humiliation", which included a strip-search.

A spokesman for the United States Attorney's Office for the Southern District of New York said in a statement that they "had been advised by the state department that, pursuant to their request, Devyani Khobragade was to have left the United States this afternoon".

Her lawyer, Daniel Arshack, later said she would return to India with her head "held high".

A US state department official said Ms Khobragade was asked to leave the United States after India had refused a request to lift her diplomatic immunity.

The charges against her remain in place, the official said.

A spokesman for the Indian Ministry of External Affairs, Syed Akbaruddin, later said Ms Khobragade had left the US and was on her way back to India.

"At the time of her departure to India, Counsellor Khobragade reiterated her innocence of charges filed against her," he said.

Reprisals

Ms Khobragade, India's deputy consul general in New York, had been handcuffed and searched after a complaint from the maid, Sangeeta Richard.

Ms Khobragade denied all the charges and in turn accused Ms Richard of theft and attempted blackmail.

Delhi ordered a series of diplomatic reprisal measures against the US, and relations between the two countries have been strained over the case.

Security barricades around the US embassy in the capital were removed and a visiting US delegation was snubbed by senior Indian politicians and officials.

And on Wednesday, the US embassy in Delhi was ordered to stop "commercial activities on its premises". India also said that embassy cars could be penalised for traffic offences.

The embassy has been told to shut down a club within its premises which includes a pool, restaurant and tennis court, NDTV news channel said.